Control mechanism



A. G. LARSON CONTROL MECHANISM Filed Aug. `19, 1943 IN VEN TOR v BY ATTORNEY `Fune 18, 1946.

Patented June 18, 1946 'UNITED STATES P'rlazNi OFFICE CONTROL MEonANIsM f Arthur G. Larson, ForestvHills, Pa., assignor to The Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Application August 19, 1943, yserial No. 499,215 1 Claim. (o1. 121-40) This invention relates to control mechanism position, and a reverse starting .position in whichV the engine is put into motion in, respectively, opposite directions usually by compressedair admitted to one or more of the cylinders, and a forward running position and a reverse running position in which fuel is admitted to the cylinders in relatively reverse sequences according to the direction of operation of the engine and the firing order of the cylinders.

One Object of the invention is the provision of a novel iiuid pressure controlled motor arranged to respond to different pressures of fluid, corresponding to different positions of a device being controlled such as the maneuvering gear of a Diesel engine, to correspondingly position said device.

According to this object the motor is controlled by iiuid pressure and embodies a .plurality of precompressed springs arranged to selectively become effective in different positions of the deand details arenot elements of the present in. l

vention. vThe inventioncomprises4 tmotor arrangements such as dened in any ofV the above objects for controllingthe positioning; of a device vhaving a plurality of different positions, such as five, as -will be readily apparent from thel description to follow.

Other objects and advantages will be apparent from the following more detailed description of the invention:

In the accompanying drawing; Fig. 1 is a diagrammatic view, partly in section and partly in.

elevation, of a fluid pressure control system for a device such as a maneuvering gear of a Diesel engine and showing in longi'tudinal vertical section, the improved fluid motor for controlling the positioning of., said gear; and Fig. 2 is a vertical cross-sectional view taken through the maneuvering gear and the fluid motor therefor shown in Fig. 1, the view of the iluid motor shown in Fig. 1 being taken substantially on the line l--I inFig. 2.

Description engine to which is connected, by one or more vice to oppose pressure of uid and cooperative. y

of fluid, in case of failure of the fluid pressure for operating said motor.

Maneuvering gears are usually provided with hand operated means for emergency manual adjustment to the different positions. According to another feature of the invention the means which operate automatically, in case of failure of the fluid pressure supply, to hold the maneuvering gear in a position to which it had previously been moved by the fluid motor, is also effective to hold said hand operated means in any selected position upon manual adjustment there- Maneuvering gears may diier from each other with respect to the number of features to be controlled and the number of different control positions, as well as in other details. These features bolts 2, a bell-like housing 3, and extending from said engine into the housing 3 centrally thereof is a hollow ,tube-like maneuvering gear shaft 4 for controlling parts (not shown) in the engine whereby starting, stopping, and reversing of the engine may be controlled. The shaft 4 may have a neutral or stop position ,for stopping-the engine, forward and reverse starting positions, and forward and reverse running positions. 'I'he means in theengine controlled by shaft 4 are not shown in the drawing and are not pertinent to the in' vention. Moreover, such parts are well knowito those skilled in the art and a further descrip.- tion or showing ,thereof is, therefore, not essential in the present application.

'I'he shaft 4 is arrangedponcentric to afsupport shaft 5, the outer end of which is carried in a cover 6 secured by screws `'i to the outer open end of housing 3. The outer end of shaft 4 engages an'inner face of cover 6 to hold said shaft operation of said lever to turn shaft 4 to the different positions above'described. These positions, of shftli and of lever I are indicated in the drawing by the following legends; Stop, Ahead start," Ahead run, Astern start and Astern run." The opening 9 is closed by a cover |4 secured to housing 3 by screws l5 and said cover' has a slot I3 providing for the movement oi.' lever I0 above mentioned.

A gear segment Il is mounted on the maneuvering gear shaft 4 in abutting relationship with lever I0 and is secured by key l2 to said shaft for turning same. Adjacent the outer face of gear segment l1 the shaft 4 is provided with an annular groove in which is disposed a ring |8 bearing against said segment and which cooperates with the shoulder on shaft 4 to hold Said segment and lever In against axial' movement on said shaft.

The teeth on gear segment I1 mesh with teeth on a horizontally arranged rack I3 disposed below the shaft 4 and movable at right angles to theaxis of said shaft for turning the gear segment and lever l0. The opposite ends of the rack are connected respectively to an ahead piston 20 supported and disposed to reciprocate in an ahead cylinder 2|, and t0 an astern piston 22 supported and disposed to reciprocate in an astern cylinder 23. The two cylinders 2| and 22 are formed integral with housing 3, and the adjacent or rear faces of said pistons are open to the interior of said housing which is open to atmosphere by way of slot I5 through which the lever I9 extends.

'I'he outer ends of the two cylinders 2| and 22 are also open, and secured thereto over stop shoulders 24 and 25 are like sleeves 26 and 2l, the outer ends of which are closed by covers 28 and 29, respectively.' A pressure chamber 3|) is thereby provided between piston 20 and cover 28, while a like pressure chamber 3| is provided between piston 22 and cover 29, and these chambers are connected respectively to pipes 32 and 33.

Slidably mounted in cylinder 2| on the pressure chamber side of piston 20 is a combined spring cage and follower 34 having at its outer end an annular outturned collar 35 arranged to cooperate with stop shoulder 24 in said cylinder to limit movement of said follower in the direction of piston 20. but providing for movement of said follower in the opposite direction into sleeve 26. At the opposite end of cage 34 is an inturned collar 35 for engaging the adjacent or front face of piston 20. One end of a coil spring 31, which is under a chosen degree of pressure, bears against collar 36, while the opposite end engages a shelf 38 in sleeve 26,

A like combined spring cage' and follower 39 is slidably mounted in cylinder 23 within Dressure chamber 3|. This cage has at one end an annular collar 40 arranged to cooperate with stop shoulder 25 to limit movement of the cage in the direction of piston 22, and at the opposite end has an annular inturned collar 4| for engagement with said piston. A coil spring 42, like spring 31 and also under pressure,.bears at one end against collar 4| while the opposite end engages a shelf 43 in the sleeve 21.

The parts are so designed that with lever ||l in "stop position as shown in the drawing, the twospring cages 34 yand 39 will be in substantial contact with the adjacent or front faces of the respective pistons 20 and 22, and the annular collars 35 and 40 will be urged into contact with stop shoulders 24 and 25 by springs 31 and 42,

respectively, whereby movement of said lever in either direction from "stop" position will be relative to one and opposed by the other of said springs. It will therefore be apparent that when pressure of iluid in both pressure chambers 38 and 3| is the same, as with both chambers open to atmosphere, the maneuvering gear lever I0 will be moved to stop" position and heid therein by the opposing forces of the two springs 31 and 42.

A spring cage 45, extending into the coil spring 31, is mounted to slide in an axial bore provided through shelf 38 in sleeve 28. The outer end of this cage is provided with an annular outturned collar 43 arranged to cooperate with shelf 33 for limiting movement of said cage in the direction of piston 20; movement in the 0D- posite direction to a position in contact with cover 23 being provided for. At the opposite end of cage 45 is an annular inturned collar 41 engagedfby one end of a precompressed coil spring 48 the opposite end of which engages the cover 28. The spring cage 34 is provided adjacent piston 20 around the inner periphery of collar 36 with' a forwardly extending cylindrical flange y48 arranged for engagement with collar 41 of spring cage 45upon movement of piston 20 in the direction of the righthand an amount sufficient for positioning the lever I0 in the astern run" position. It will be noted that this movement of piston 20 is opposed only by pressure of spring 31 and that further movement of said piston in the'same direction will then be opposed by the additional force of spring 48, and may be limited by engagement of collar 35 on cage 34 with shelf 38, or by engagement of collar 46 on cage 45 with the cover 28. Upon such engagement the piston 28 will occupy a position in which lever .I0 will be in the astern stop position.

A cage 5| like cage 45 extends into pressure chamber 3| through an axial bore provided in shelf 43 and has at its outer end an annular collar 52 arranged to cooperate with the outer surface oi' shelf.43 to limit inward movement of said cage, outward movement of the cage being limited by contact with cover 29. A spring 53 extending through cage 5| engages one end thereof while its opposite end engages the cover 29, this spring being like spring 48 and being conned by said cage under the same degree of pressure. 'Ihe spring cage 39 is provided adjacent piston 22 and within the spring 42 with a forwardly extending cylindrical flange 54 arranged for engagement with the adjacent end of cage 5|. With the parts positioned'as shown in Fig. 2, the distance between the flange 54 and the adjacent end of cage 5| is such as to allow movement of piston 22 against spring 42 just into contact with cagev 5| when lever I0 occupies the position indicated by the legend Ahead run. Further movement of piston 22 in the same di- `rection and againstl the additional force of spring 53 may be limited by contact between shelf 43 and the adjacent end of spring cage 39 or between cage 5| and cover 29, and in which position lever ||l will occupy the position indicated by the legend Ahead start." a

Powefmovement of the maneuvering gear shaft 4 to any selected one oi.' its different positions is arranged to be obtained by supply of fluid at different selected pressures, corresponding to the desired position, to either pipe 32 or pipe 33 while maintaining the'other pipe open to the atmosphere.

For thus controlling the pressure of fluid in pipes 32 and 33. said pipes may be connected to V any desirable and suitable control means such device 60 employed in the present application are not pertinent to lthe invention, the following description thereof will be limited to only that deemed essential to a clear understanding of the i l invention.

The control valve device 60 comprises a. man- Y ual operating lever` 6| having a neutral or stop" position in which it is shown in the drawing, and at one side of stop? position two positions indicated bylines bearing the legends Ahead run and "Ahead start," and 'at the opposite side of stop position two positions indicated by lines bearing the legends Astern run" and "Astern start, it-being noted that these positions correspond in name and relative disposition to those of the maneuvering gear shaft 4 and lever l0.

The control device 6|) further comprises valve means (not shown) arranged to be conditioned by lever 6| when in stop position to open both of the pipes 32 and 33 to the atmosphere, and which is operative upon movement of said lever in a clockwise direction, as viewed in the drawing, to supply fluid from any suitable source,

such as a pipe 62 supplied with fluid under pressure from a supply reservoirA 63, to the pipe 32 at a pressure proportional to the extent of movement of the lever away from stop position, while maintaining the pipe 33 open to the atmosphere. It will thus be seen that in the ahead run and ahead start positions of lever 6| two differentpressures of fluid will be provided in pipe 32, suchfor example as 35 and 70 pounds, respectively.

. 'Upon movement of lever 5| in the opposite direc- Assuming that the engine is connected to va ships propeller and it is desired to cause forward or ahead movement of the ship, the operator will move lever 6| 'from stop position to ahead start position to thereby supply iiuid to pipe 32 at the chosen pressure, such as '70 pounds,

Awhile maintaining pipe 33 open to the atmosphere.v The force of the two springs 42 and 53 are such-that the pressure of fluid thus supplied through pipe 32 to pressure chamber 30 to act on the ahead piston 29 will move' said piston and thereby the rack I9 and astern piston 22 initially against spring 42 until cage 39 engages cage and then against the additional force of spring 53 to the position defined by contact between collar 40 on the outer endof cage 39 and shelf 43 in the sleeve 21.' This movement of rack I9 turns the gear segment and thereby the maneuvering gear shaft 4 and lever I0 to the position indicated by the legend "Ahead start,"

it being noted that said position is deiined by contact between the end of cage 39 and shelf 43.

. After -thel engine is then startedin any con-` ventional manner, the operator moves lever 6| back to the position bearing the legend Ahead run" for thereby reducing the pressure of fluid in pipe 32 to the chosen lower degree of 35 pounds while still maintaining ypipe 33 open to the atmosphere. This lower pressure effective in chamber 30 on thel ahead piston 20'creates a force less than the combined opposing forces of .the two springs 42 and l53 but greater than the force of spring 42, by itself, with the astern piston 22 in a position in contact with cage 5| and with said cage in contactv with shelf 43. As a result the combined forces of springs 42 and 53 will move piston 22, rack I9, and piston 20 back` s thereby of rack I9 and piston 20 will stop in this l position.

This movement of the rack I9 and thereby of the gear segment Il will turn the maneuvering gear shaft 4 from the yahead start position back to the ahead run" position in which it will then be maintained as long as fluidv at 35 pounds is maintained in pipe 32.

When subsequently it is desired to stop the engine, the operator returns lever 6| to stop position for thereby opening pipe 32 and piston chamber 30 to the atmosphere. When the pressure of iluid in chamber 30 effective on piston 20 is thus reduced to that of the atmosphere, spring 42 acting on piston 22 moves said piston back to the position in which the annular collar 40 on cage 39 engages the stop shoulder 25 and in which position the piston '20 substantially contacts the cage 34. The actuating force of spring 42 on piston 22 being thus removed, the two pistons and the rack I9 stop in the stop position shown in the drawing.- This movement of 'piston 22 and rack I9 acts through the gear segment to turn the maneuvering gear shaft 4 and thereby the lever I0 back to` their stop positions for stopping the engine.

If the operator now desires to cause operation of the engine in the opposite 01 astern direction, he first moves lever 6| to the lastern start position for thereby providing in pipe 33 iiuid at the chosen degree of pressure, such as 70 pounds,

while maintaining pipe 32 to the atmosphere. This pressure of fluid provided inl pipe 33 and vthereby in chamber 3| being effective on piston 22 moves said piston and thereby Vthe rack I9 and piston 20 in the direction ofthe right-hand to a position defined by contact between collar 35 on cage 34 and shelf 38 in the'sleeveZS, thismovement being obtained since the springs 31 and 48,

which become successively eiective to oppose such movement, are like springs42 and 53 and thus provide Va force less than that provided on piston 22 by pressure of fluid. The piston 22 as it thus moves actuates the gear segment to turn the maneuvering gear shaft 4 and lever I0 to the astern start position for thereby starting the 7 in pipe 33 to the chosen lower degree of 35 pounds while maintaining pipe 32 open to the atmosphere. This reduction in pressure in cham.- ber 3| on piston 22- produces a force which is less than that'provided by the combined pressures of springs 31 and 4B acting together but which exceeds that of spring 31 by itself when the piston 20 is in the position defined by contact between the cages 34 and 45 when collar 46 on cage 45 is in contact with shelf 36. As a result, the combined force of the two springs 31 and 48 will move the pistons 20 and 22 back to the position in which collar 46 on cage 45 contacts shelf 38 for removing the force of spring 48 from the piston 20, in which position said pistons and thereby rack I9 will be stopped. This movement of rack I9 will rock the gear'segment |1 and turn the maneuvering gear shaft 4 and lever l back to the astern run position in which position said parts will remain until it is subsequently desired to stop the engine or cause reverse movement thereof.

In order to stop the engine, the operator returns lever 6| to stop" position for thereby opening pipe 33 to the atmosphere along with pipe 32. A complete release of fluid under pressure from chamber 3| then occurs and the pressure of spring 31 on piston 20 then moves said piston and thereby the rack I9 and piston 22 back to the position in which collar 35 on cage 34 engages the stop shoulder 24 in cylinder 2|, in which position, the piston 22 substantially contacts the adjacent end of cage 39, so that movement of the two pistons and thereby of therack I9 will cease. The rack I9 as it is thus returned to its neutral position actuates the gear segment I9 to return the maneuvering gear shaft 4 and thereby lever I0 to their stop" position for stopping the engine.

It will be noted that when the maneuvering gear shaft 4 and lever l0 are in their ahead run position they are held in this position by pressure of fluid supplied through pipe 32 and effective in chamber 3 0 on piston20. Likewise, with the maneuvering gear shaft 4 and lever I0 in the astern run position they are held in this position by pressure of fluid supplied through pipe 33 and effective in chamber 3| on piston 22. With the maneuvering shaft 4 and lever I0 in either of the two run positions it will therefore be apparent that failure of the pressure of fluid effective on piston 20 or 22, as due to breakage of the control pipe 32 or 33, or the uid pressure supply pipe 62 would tend to result in automatic return of the maneuvering gear shaft 4 and of lever I0 to their stop" position and cause undesired stopping of the engine. According to the invention such undesired stopping of the engine in case of failure of the iiuid pressure supply is however prevented by means which will now be described.

The housing 3 is provided above the support shaft 5 with aboss 65 having a through bore containing a plunger or piston 66 which is movable in said bore in directions toward and away from oneside of lever I0. The end of the bore which is adjacent lever I0 is closed by a cap 61 whilev the opposite end is closed by a cap 68 and interposed between these caps and the adjacentends of the boss are sealing gaskets 69 and 69a, respectively. A pressure chamber formed between cap 61 and piston 66 is -constantly open preferably toA the fluid pressure supply pipe 62 as shown in Fig. 1. 'I'he piston 66 has a stern 1| projecting into chamber 10 and arranged to engage gasket 69 and containing a ring gasket 64 engaging the.

peripheral surface of said stem for preventing leakage of fluid under pressure from chamber 1li past said stem to the atmosphere. A rod 13 projecting through a suitable bore in cap 68 extends from the outside of said cap into a chamber 14 provided at the opposite side of the piston, and the inner end of rod 13 is secured centrally to said piston, as by screw-threaded engagement. A spring 15 contained in chamber 14 has one end supported by cap 68 while its opposite end bears against the piston 66, this spring being under compression and therefore constantly effective for urging said piston in the direction of lever I Il. The piston 66 is provided in chamber 14 with an annular sealing bead I6` for engagement with.

A nob 11 is secured to the outer end of rod 13 for gripping by the operator.

When an adequate or safe pressure of fluid is effective in the supply reservoir 63 and supply pipe 62, such pressure acting in chamber 10 on piston 66 is arranged to move said piston to the position in which it is shown in the drawing in which the bead 16 is in sealing contact with the gasket 69a under cap 68, and to then hold said piston and thereby the rod 12 in this position, so long as this pressure condition exists.

'I'he lever l0 is provided on the side adjacent piston 66 with an integrally formed arcuate shaped arm 18 disposed to move past the end of stem 12. This arm has a recess 19 arranged to receive the end of stem 12 with lever I0 in stop" position; a recess arranged to receive stem 12 with lever I0 in the "ahead run position and a recess 8| arranged to receive said stem with saidlever in the astern run position.

With piston 66 and thereby stem 12 held in the position shown in Fig. 2 when the pressure of uid in reservoir 63 and supply pipe 62 is at a. safe degree, it will be seen that the maneuvering gear shaft 4 and lever l0 can' be moved by pistons 20 and 22 relative to said stem and inthe manner above described. However, if with lever I0 and the maneuvering gear shaft 4 in either the ahead run" or the "astern run" position the pressure of fluid in reservoir 63 and supply pipe 62 should fall to a degree below that considered safe as determined by the pressure of spring 15 on piston 66, it will be noted that said spring will move the piston 66 in the direction of the 1efthand,-as viewed in Fig. 2, for thereby moving the stem 12 into either recess 80 or 8|, respectively, which recess is aligned to receive said stem with the lever I0 in such position. With the stem 12 thus disposed in either of the recesses 80 or 6|, further loss of fiuid pressure from pipe 62 cannot result in automatic and undesired movement of the maneuvering gear shaft 4 and lever I0 back to stop position, or in other words, the piston 66 will automatically operate in case of failure of the fluid pressure supply on the actuating plston 20 or 22 to hold the lever I0 in the preadjusted run position. The recess 19 provided to receive the piston stem 12 in "stop" position of lever I0 is of no consequence insofar as the operation just described is concerned.

The lever I0 is provided for manually adjustsure or to breakage of some part of the motor, yunder which condition it is desirable to have some means for assuring that said' lever will remain not only in the running positions as above described but also in stop position. The recess 19 is provided in lever I0 for receiving the stem ll2 in the stop position of said lever to accomplish this end. The release of lever l0 for manual movement out of stop" position or out of either run position for controlling the engine c by manual operation of lever lll may be effected by the operator grasping the nob ll and pulling same outwardly againstthe opposing force of spring l as will be apparent.

It will be noted that with the uid motor in an. operative condition at a time when there is no fluid` pressure in reservoir 63, the pistons 2li and 22 will be moved upon manual operation of lever i@ to turn the shaft d to its dii-ferent' positions. As a result springs 39 and E3 will oppose movement of lever to the ahead start position and upon release of manual pressure on said lever will automatically return said lever and shaft l to the "ahead run position in which position the piston stem l2 will automatically act to secure said lever and shaft against further movement by spring 3S. The same is true with respect to the astern start positionand astern run" ,position due to the action of springs 'l and d8 on piston 20`and this is desirable in that it avoids the possibility oi the operator. leaving the lever lli and shaft 4 in either start position when it is intended that these parts be in the adjacent run position.

Summary i ness and accuracy in accordance with pressure of fluid provided in the motor corresponding to the desired selected position thereof. Of importance is the structure which prevents any change of adjustment of the device in case of failure of iiuid pressure on the'power motor and this structure is also arranged to cooperate with the means for manually operating the gear for holding said means in certain selected' positions thereof.

Having now described my'nvention, what I claim as new and desire to secure b'y letters Patent, is:

In combination, a source of fluid under pressure, a casing, a rockable control member in said l casing having a neutral position and at one side of neutral position. second and thirdy positions and at the opposite side o f neutral position fourth and fifth positions, said second and fourth positions being arranged intermediate said neutral position and said third and fifth positions, respectively, a hand operated lever having one end secured to said member, said lever extending 5 through a slot in said casing to the exterior thereof for operation by an operator to rock said l member to its different positions, piston means in said casing operatively connected to said member and having positions corresponding to those of said member, said piston means being operable upon. supply of fluid under pressure to one chamber, when iiuid under .pressure is released from a second chamber, to rock said member out of neutral position to said second or third posi- 1d tions and being operable Yupon supply of fluid under pressure to said second chamber, when fluid under pressure is released from said one chamber, to rock said member out of neutral position to said fourth and fth positions, an operators control valve device' selectively operable to either supply iiuid under pressure from said source to either one of said chambers or to release uid under pressure from the last named chamber, while at the same time opening the other chamber to atmosphere, spring means in said casing arranged to oppose movement of said piston means by fluid under pressure supplied to either one of said chambers and operable upon release of fluid under pressure from the last named chamber to operate said piston means to move said member and lever to their neutral positions, locking structure associated with said lever, looking means carried by said casing and adapted to cooperate with said locking structure in said neutral, second and fourth positions of said member and lever to secure said member and lever against movement, said structure rendering said locking means ineffective to secure said member and ylever against movement from 4 said third and aan positions to said second and fourth positions, respectively, spring means acting on said locking means and operative to urge said locking means into cooperative relation with l-said locking structure, means operative manually to move said locking means out of cooperative relation with said structure, a piston in said casing subject to pressure of fluid in a chamber and to opposing pressure of the last named spring means and operable when the pressureof fluid in the last named chamber exceeds thatof said last'named spring means to move said locking means out of cooperative relation with said structure and when of a lesser degree to render the last named spring -means elective to urge said locking means into cooperative relation with said structure, and a fluid conduit establishing a. fluid pressure supply communication, direct and independently of said operators control valve device, between said source and last named chamber o whereby said piston is constantly subject in the last named chamber to the .pressure of fluid in said source. .ARTHUR G. LARSON. 

